On April 1, 1980, Frank Lopez, a 23-year-old Hispanic man, was shot and killed at Mario’s Transmission, an auto repair shop at 2650 W. 44th Avenue in Denver. He died alongside his stepfather, Mario Horta; both men succumbed to fatal gunshot wounds at the scene. The attack turned a workplace into a double homicide and left the family with enduring questions about motive and responsibility.

The Denver Police Department investigated but no arrests were announced and the case went cold. The department continues to list the deaths as unsolved and is seeking information that could break the case. If anyone knew Frank, Mario, worked at or near the shop, or has information about that night, please come forward and share what might help bring answers.